My answer to the question Notarizing and Apostilling US Documents was accepted as the best answer, then unaccepted (probably because the question owner accidentally double-clicked), and then re-accepted.

The end result is that I received 25 reputation from my post, when I should only have received 15 (re-accepting the answer should have canceled out the unaccept penalty, not re-applied the accept bonus).

I worked around the issue for now by setting the unaccept penalty from -5 to -15.